• Introduction
• Recent Soil Moisture Monitoring observations
• Speedo assessments - change in overall soil moisture at a particular site
• Speedo soil moisture graphs
  • Mallee
  • Wimmera
  • North Central
  • North East
  • Gippsland cropping
  • South West

The soil moisture monitoring project, with the use of underground probes, provides real-time soil water content data to Victoria’s farmers.
Monitoring sites have been set up in cropping regions throughout the state by Agriculture Victoria.

The sites record soil water content at one source point from 30 centimetres down to one metre as a reference point for a paddock.

To access information provided in the graphs, log onto the new Agriculture Victoria soil moisture monitoring dashboard.

No login or passwords are required, and speedos are automatically updated.

Figure 1: November rainfall deciles for Victoria

Decile 8 - 9 rainfall for parts of the Wimmera and Mallee but the West Wimmera and south of Swan Hill were average.

The majority of North Central Victoria had a soft finish with cool and above average rainfall that resulted in high yielding crops, yet retaining a good portion of deep soil moisture reserves.

Districts with decile ten had rainfall totals to initiate an early build-up of soil moisture profiles for the 2022 cropping season.  Gippsland cropping areas were wetter at decile 8 to 10 for the month.

Figure 2: Rainfall deciles for January

The western border of the Mallee (from north to south) recorded ‘average’ rainfall for January (decile 6 in Murrayville and Kaniva), which increases to ‘above average’ moving to the east (decile 8 in Werrimull and Walpeup).

The far north and north (Mildura and Ouyen) received ‘very much above average’ rainfall (decile 10) for January.

Southern Mallee - Hopetoun and Birchip have recorded ‘average’ rainfall The North Central recorded ‘very much above average’ (decile 9 - 10) rainfall for January in the west of the catchment (Swan Hill and St Arnaud) and reduces to ‘above average’ (deciles 8 - 9) as weather systems move east to Echuca and Bendigo.

Cropping districts with decile 10 for January have had opportunities to build soil moisture profiles.

Figure 3. February rainfall deciles for Victoria

‘Average’ to ‘below average’ rainfall during February in Victorian cropping regions with some districts as dry as a decile 1.

http://www.bom.gov.au/climate/maps/rainfall/?variable=rainfall&map=percent&period=cmonth®ion=vc&year=2021&month=11&day=21

Figure 4. Most recent rainfall (February 28 and March 1) - impacts not recorded in this report

Varying rainfall totals and thunderstorm activity with highest totals around Wodonga, Ouyen, Horsham and Kerang and amazingly some areas with no rain in between those districts showing the random nature of the storms.

Live updates to soil moisture conditions can be viewed on the SMM dashboard.

https://extensionaus.com.au/soilmoisturemonitoring/

Soil moisture measurements collected by Agriculture Victoria in the past four months show there have been some opportunities to build a soil moisture profile since late spring.  This has been in the months of November and January with storm cells impacting different parts of the state. 

December and February were dry.  Deep moisture increases in the past four months have ranged from 10 - 40 per cent across the state.

There is still a range of low to low/moderate soil moisture conditions in the Mallee and patches of the Wimmera. Soil moisture probe data shows that generally the soft finish last spring did not deplete all the moisture reserves in the profile.

Spring rainfall was a major contributor to yield and residual moisture from 2021 still exists in varying volumes deep in the profile.

Central Victoria and North East Victoria have moderate soil moisture conditions and patches that are wetter. History shows that a month of decile 8 - 10 rainfall in summer will be enough for some positive improvements.

Districts with two months’ of 8 - 10 decile rainfall in the past four months with good weed control will have profiles well set up for the 2022 cropping season. Further rain in March should raise confidence and provide opportunities for a range of crop rotation options.

Note - Some soil moisture monitoring speedos below have been temperature adjusted to better reflect the current moisture conditions.

Note -  use extensionaus.com.au/soilmoisturemonitoring to monitor the changes to the sites relevant to you inbetween the next reporting period and following rain events

Werrimull stacked individual soil moisture graph – 2021/2022 view
Low biomass wheat in 2021 and a soft finish left some moisture in the profile. November rain infiltrated down to 40 centimetres. January rain moved down to 50 centimetres for an overall increase of 15 per cent in total deep moisture.

Ouyen stacked individual soil moisture graph – 2021/22 view

October rainfall was enough to meet crop demands for grain fill last spring. Low to moderate residual moisture still exists at many depths. Rainfall in late January was enough to infiltrate down to 60 centimetres. There has been a 20 per cent deep moisture increase in the past four months.

Rainfall in early November paused deep moisture depletion last spring as the crop obtained the freely available water from the top horizon for grain fill. This left half the deep moisture available for the 2022 crop. There has been a 15 per cent moisture increase to the residual moisture in the past four months.

Normanville stacked individual soil moisture graph – 2021/22 view

Some residual moisture has been left at depth after the vetch hay crop was cut in late September, effectively stopping plant water use.  Rain at the end of January has improved the moisture profile by 10 per cent with moisture wetting down to 30 centimetres.

The vetch crop was cut for hay in September last year, but paddock conditions were dry.  Rainfall was beneficial in late November to add to soil moisture, but there have been no changes over the summer period.

Sheep Hills stacked individual soil moisture graph – 2021/22 view

November rain was beneficial for late pod fill in canola and conserved some deep soil moisture for this season’s crop. There have been two periods where moisture infiltration has been observed with the moisture probe after rain events in late November and late January.

There have been some small increases to soil moisture during the past four months. Please follow the link to the soil moisture monitoring dashboard to obtain the most recent changes with the 1 March rain event in the Wimmera.

Coonooer Bridge stacked individual soil moisture graph – 2021/22 view

Moisture has moved down to 60 centimetres in the past four months and there has been an overall increase of 38 per cent moisture.  This was confirmed with a soil core validation in mid-February (see image below).

Canola was windrowed on 9 November, ceasing crop water use and permitting infiltration of moisture with later rain events in the month.  Like many central Victorian sites, decile 8 - 10 rainfall in January contributed to building the bank of soil moisture. There has been a 35 per cent moisture increase in the past four months, setting the district up with high cropping confidence this season.

Youanmite stacked individual soil moisture graph – 2021/22 view

Rain on 12 November 2021 (which was predominately located in North East Victoria) provided the moisture for successful grain fill of the wheat. This conserved deep soil moisture for this season’s crop. Decile 10 rainfall for January has banked additional deep soil moisture.  There has been a 25 - 30 per cent moisture increase in the past four months. Areas in North East Victoria with highest January rainfall on record are fully wet in the lower areas of the paddocks.

The Giffard West site was drying down in January and early February with crop regrowth after spending half of 2021 in a saturated state. Waterlogging impacted crop performance and harvesting logistics. While the majority of the state was below average rainfall during February, Gippsland was average and this has created some small moisture increases.

The long season wheat crop used a surprising amount of soil water late in the season during November and December last year but this contributed to a high yield. This left the soil dry. There have been some small moisture increases during January.

Soil water increases during the past four months equal 40 per cent and as repeated numerous times through this report, this was a combination of November and January rain events.  November contributed to pod fill with the long-season canola and conserved deep soil moisture and January rain provided deep infiltration.